import java.util.Scanner;

/**
 * DP34 【模板】前缀和
 * https://www.nowcoder.com/practice/acead2f4c28c401889915da98ecdc6bf?tpId=230&tqId=2021480&ru=/exam/oj&qru=/ta/dynamic-programming/question-ranking&sourceUrl=%2Fexam%2Foj%3Fpage%3D1%26tab%3D%25E7%25AE%2597%25E6%25B3%2595%25E7%25AF%2587%26topicId%3D196
 */
public class Solution {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt(), q = in.nextInt();
        int[] arr = new int[n + 1];

        for(int i = 1; i <= n; i++) {
            arr[i] = in.nextInt();
        }

        long[] dp = new long[n + 1];
        dp[0] = arr[0];
        for(int i = 1; i <= n; i++) {
            dp[i] = dp[i - 1] + arr[i];
        }

        for(int i = 0; i < q; i++) {
            int a = in.nextInt(), b = in.nextInt();
            long x = dp[b] - dp[a - 1];
            System.out.println(x);
        }
    }
}